A. Field of the Invention
This relates to dock safety and insuring that a truck and trailer combination is safely moved after the loading or unloading of the trailer. The loading and unloading of a trailer is frequently accomplished at a loading dock. As the workers load or unload a trailer, it is imperative that the truck that is attached to the trailer not be allowed to move to avoid the risk of personal injury. This device is a simple way to inform the driver when not to move the trailer and when the trailer can be safely moved.
B. Prior Art
There are many other prior art references to dock warning systems and a representative example of this can be found at Metz, U.S. Pat. No. 5,964,059. This patent teaches a safety pole that is positioned in the front of the vehicle and is controlled by a motor driven drum.
Nowak, U.S. Pat. No. 6,312,214 is another patent that teaches a method for improving safety in the loading or unloading process. However, this system uses an actuator with a plurality of different colored lights that controls the operation and movement of a barrier in the front of the truck cab.
Another dock safety apparatus includes Rennick and can be found at U.S. Pat. No. 4,122,629. Again, this is also a way to alert a driver when to move or not to move but uses an electrical system that controls the movement of a gate positioned near the rear of the trailer. An electrical switch positioned on a chock against which one of the tires of trailer rests controls the operation of the switch.
The current device is different than the prior art because the current device uses a mechanical apparatus to warn a driver and to advise a driver when the truck and trailer combination can be safely moved. An important feature of the current device is that the worker must physically pull the flag and block the entrance to the trailer prior to the trailer being allowed to move. This device is a mechanical device and does not rely on the operation of any electrical circuitry to operate the system. The worker is personally responsible for signaling when a move may be safe.